Actor Scott Baio is cooperating with the FBI and Twitter to determine who sent death threats to his Twitter account, in response to a post Baio tweeted that contained an unflattering photo of First Lady Michelle Obama.

Baio, a vocal Republican best-known for his starring role on the 1980's sitcom "Charles in Charge," posted the photo Tuesday night, accompanied by the words, ""WOW He wakes up to this every morning."

A torrent of criticism quickly followed, and Baio (shown here with wife Renee Sloan) appears to have spent the next 12 hours responding to the attacks and occasionally blocking people from communicating with him on the site.

It wasn't until mid-morning Wednesday that the notes grew noticeably more menacing.

Baio later posted:

PLEASE NOTE: The FBI has been contacted & we have a file number for the threats, along with twitter support. Thx

Unlike the digitally altered photo of Mrs. Obama that caused controversy last year when it was temporarily removed from Google, this photo shows the first lady making a surprised face; the kind of picture that could happen to anyone, especially someone photographed as frequently as Obama is.